Your Plugin works great.
It would be awesome if we can set custom dimension using this plugin,
I think this can be done with small changes,
if enabled we can pass value using variable which is sent with pageview,
ga('create', 'UA-12345-1', 'auto');
ga('set', 'dimension1', dimensionValue); // Set the custom dimension value
ga('send', 'pageview');
For Reference:
20 Ways To Use Google Analytics Custom Dimensions | Bounteous
I am asking this because we use this to filter internal traffic from analytics and for other purpose also.